In the fields of industrial networks connecting industrial apparatuses in a factory, in-vehicle networks connecting a controller in the vehicle, and the like, high real-time performance is required. In recent years, Ethernet (registered trademark) has been used increasingly in industrial networks, in-vehicle networks, and the like, and various real-time Ethernet standards have been proposed. For example, a technique has been disclosed. In the technique, transmission control is performed on the basis of the priority, the guaranteed bandwidth, the transmission cycle or the transmission interval of the frame, and the like.
However, conventional art has difficulty in performing scheduling to perform strict transmission timing control in the unit of frames within the range of the transmission possible time dynamically changing on the basis of transmission scheduling information assigned in advance to the transmission queue. Specifically, conventional art has difficulty in performing scheduling to perform transmission timing control with high accuracy.